We address the problem of video streaming packets from an Access Point (AP)
to multiple clients over a shared wireless channel with fading. In such
systems, each client maintains a buffer of packets from which to play the
video, and an outage occurs in the streaming whenever the buffer is empty.
Clients can switch to a lower-quality of video packet, or request packet
transmission at a higher energy level in order to minimize the number of
outages plus the number of outage periods and the number of low quality video
packets streamed, while there is an average power constraint on the AP.
We pose the problem of choosing the video quality and transmission power as a
Constrained Markov Decision Process (CMDP). We show that the problem involving
$N$ clients decomposes into $N$ MDPs, each involving only a single client, and
furthermore that the optimal policy has a threshold structure, in which the
decision to choose the video-quality and power-level of transmission depends
solely on the buffer-level.

本文研究了如何通过选择视频质量和发射功率来最小化视频流中断及低质量视频数据包的数量，同时满足 AP 的平均功率约束。作者将问题建模为受限制的马尔可夫决策过程，并证明了最优策略具有阈值结构。